some flags are unexpectedly added to table info meta

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

https://github.com/pingcap/tidb/blob/master/pkg/planner/core/find_best_task.go#L2446-L2452
And

tidb/pkg/executor/show.go

Line 143 in f383e0e

retType.SetFlen(valLen)

2. What did you expect to see? (Required)

N/A

3. What did you see instead (Required)

N/A

4. What is your TiDB version? (Required)

master

[wshwsh12]

Fixed by #55463 and #55309